[Intel-gfx] Speed boost disabling RCC clock gating ECO

[Peter Clifton]

On Sat, 2010-10-30 at 03:34 +0100, Peter Clifton wrote:

> sudo intel_reg_write 0x21D0 0x1000207
> Value before: 0x307
> Value after: 0x207
> 
> 
> This boosted FPS of my displaylist frame benchmark from 35fps to 37fps.
> 
> This was clearing bit 8 of ECOSKPD, which is controlling the following
> ECO:
> 
> Clock gating for the RCC (Disable one clock gate cell)

And the obligatory profile.. (promise, this is the last one I'll send
before someone comments on the others. It is 3:50AM here!)

I'm not sure quite how repeatable the profiles are, but this is the same
frame (in a displaylist), with same test conditions. (CPU forced to top
speed and out of C-states with two busy-loop programs to keep the cores
busy). The profile does look somewhat different.

Best wishes,

-- 
Peter Clifton

Electrical Engineering Division,
Engineering Department,
University of Cambridge,
9, JJ Thomson Avenue,
Cambridge
CB3 0FA

Tel: +44 (0)7729 980173 - (No signal in the lab!)
Tel: +44 (0)1223 748328 - (Shared lab phone, ask for me)
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